Retaining pin with self biasing keeping means

ABSTRACT

A retaining pin with self biasing keeping means has a head and a tubular pin that has a plurality of detent fingers on its end. The detent fingers are formed by slitting and deforming the ends of the pin. The detent fingers are bent to extend beyond the outside diameter of the pin with the forward ends terminating in a diameter smaller than that diameter. As the pin is inserted in a matched opening, the detent fingers compress to allow the pin to penetrate the opening and then return to their original position to retain them therein. To remove the pin, the process is reversed. The instant retaining pin with self biasing keeping means is conducive to modern mass production methods of production such as cold heading.

BACKGROUND OF THE INVENTION

Almost as soon as tools were invented, it became apparent that having ameans to keep one part connected to another was very important.Throughout history many solutions to this problem have been found suchas pins with cotter pins, retaining rings, clevis pins with cotter pinsor detent balls. One of the problems with both cotter pins and retainingrings is that they require an additional part. Additionally, because ofthis, it is easy to lose the pin or ring requiring obtaining a new one.The clevis pin with detent balls overcomes this limitation since thedetent balls are self contained, they are more complex and require aspring and retaining means to keep the detent balls contained.

There is a need for a simple, easily manufactured retaining pin thatsolves the problem of securing a connecting pin without the limitationof the prior art.

SUMMARY OF THE INVENTION

A retaining pin with self biasing keeping means has a head and a tubularpin that has a plurality of detent fingers on its end. The detentfingers are formed by slitting and deforming the ends of the pin. Thedetent fingers are bent to extend beyond the outside diameter of the pinwith the forward ends terminating in a diameter smaller than thatdiameter. As the pin is inserted in a matched opening, the detentfingers compress to allow the pin to penetrate the opening and thenreturn to their original position to retain them therein. To remove thepin, the process is reversed. The instant retaining pin with selfbiasing keeping means is conducive to modern mass production methods ofproduction such as cold heading.

Other features and advantages of the instant invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a retaining pin with self biasing keeping meansaccording to an embodiment of the invention.

FIG. 2 is an end view of the retaining pin shown in FIG. 1 according toan embodiment of the invention.

FIG. 3 is an end view of an alternative embodiment of the pin shown inFIG. 1.

FIG. 4 is a side view of a retaining pin with self biasing keeping meansaccording to another embodiment of the invention.

FIG. 5A is a side view of a retaining pin with self biasing keepingmeans as it is inserted in a typical part.

FIG. 5B is a side view of a retaining pin with self biasing keepingmeans as it is inserted in a typical part showing compression of thedetent fingers.

FIG. 5C is a side view of a retaining pin with self biasing keepingmeans as it is inserted in a typical part showing the detent fingersreturning to a normal position.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, reference ismade to the drawings in which reference numerals refer to like elements,and which are intended to show by way of illustration specificembodiments in which the invention may be practiced. It is understoodthat other embodiments may be utilized and that structural changes maybe made without departing from the scope and spirit of the invention.

Referring to FIG. 1, a retaining pin with self biasing keeping means 100is shown having a pin portion 110 that is a hollow cylinder having anoutside diameter and an inside diameter. A head 130 is formed at one endto keep pin 110 from moving past a desired position. A plurality ofdetent fingers 120 are provided to provide the biasing means toretaining pin 110 without the need for cotter pins, retaining rings orother detents.

As shown in FIG. 2, four detent fingers 120 are formed in the end of pin110 by slitting and then deforming the ends so that a portion of detentfingers 125 extend past the outside diameter of pin 110. Similarly, fivedetent fingers 120 are shown in FIG. 3. Of course other numbers ofdetent fingers can be used depending on the particular application. Ingeneral, the smaller the fingers, the less force required to deform themto fit within the selected opening.

Referring now to FIG. 4, a retaining pin with self biasing retainermeans is shown having a head 130 and tubular pin 110. In thisembodiment, a plurality of detent fingers 125 is shown having a profileterminating in a smaller diameter to aid insertion into a part. Again,different profiles may be used without departing from the spirit of theinvention and should be realized to be within the scope of thisdisclosure.

Now referring to FIGS. 5A through 5C, retaining pin 110 is pressedagainst an opening 150 in a part 140. As force is applied, detentfingers 125 compress thus reducing the effective diameter allowing pin110 to fit within opening 150. As pin 110 passes through opening 150,detent fingers 125 return to their original non-compressed state andprovide biasing to retain pin 110 without further means. To remove pin110, the process is reversed.

Retaining pin 110 is made of a resilient metal that allows forming suchas aluminum or steel. The entire pin may be heat treated to provide theneeded flexibility as is known in the art. Additionally, the pin may beheat treated after forming to allow easier manufacturing. Of courseother materials may be used such as nylon, etc. as is known in the artas long as the detent fingers are compressible and then return to theiroriginal position. Additionally, the detent fingers could be a separatepiece or pieces that are attached using a suitable method such aswelding. One of the advantages of the present invention is that is canbe inexpensively produced in mass production using a process such ascold forging (also known as cold heading). This greatly reduces the costover many of the prior art retaining pins.

Although the instant invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art.

1. A retaining pin with self biasing keeping means comprising: a pinhaving an outside diameter and an inside diameter; a head portion forrestraining movement of said pin past said portion; a plurality ofdetent fingers radially disposed along an opposite end of said pin; andsaid plurality of detent fingers being adapted to have a portion thatextends beyond said outside diameter wherein when said pin is insertedin a matched opening, said detent fingers being adapted to compress andreturn to an original position to retain said pin therein.
 2. Theretaining pin with self biasing keeping means according to claim 1wherein said plurality of detent fingers are formed by deforming saidopposite end.
 3. The retaining pin with self biasing keeping meansaccording to claim 1 wherein said plurality of detent fingersterminating in a diameter smaller than said outside diameter.